Electrochromic window fabrication methods

ABSTRACT

Methods of manufacturing electrochromic windows are described. An electrochromic device is fabricated to substantially cover a glass sheet, for example float glass, and a cutting pattern is defined based on one or more low-defectivity areas in the device from which one or more electrochromic panes are cut. Laser scribes and/or bus bars may be added prior to cutting the panes or after. Edge deletion can also be performed prior to or after cutting the electrochromic panes from the glass sheet. Insulated glass units (IGUs) are fabricated from the electrochromic panes and optionally one or more of the panes of the IGU are strengthened.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/267,260, filed on Feb. 4, 2019 and titled “ELECTROCHROMIC WINDOWFABRICATION METHODS,” which is a continuation of U.S. patent applicationSer. No. 15/226,835, filed on Aug. 2, 2016 and titled “ELECTROCHROMICWINDOW FABRICATION METHODS,” which is a continuation of U.S. patentapplication Ser. No. 14/740,114 (now U.S. Pat. No. 9,513,525), filed onJun. 15, 2015 and titled “ELECTROCHROMIC WINDOW FABRICATION METHODS,”which is a continuation of U.S. patent application Ser. No. 13/431,729(now U.S. Pat. No. 9,102,124), filed on Mar. 27, 2012 and titled“ELECTROCHROMIC WINDOW FABRICATION METHODS,” which is a continuation ofU.S. patent application Ser. No. 12/941,882 (now U.S. Pat. No.8,164,818), filed on Nov. 8, 2010 and titled “ELECTROCHROMIC WINDOWFABRICATION METHODS;” each of these applications is hereby incorporatedby reference in its entirety and for all purposes.

FIELD OF INVENTION

The invention relates generally to electrochromic devices, moreparticularly to electrochromic windows.

BACKGROUND

Electrochromism is a phenomenon in which a material exhibits areversible electrochemically-mediated change in an optical property whenplaced in a different electronic state, typically by being subjected toa voltage change. The optical property is typically one or more ofcolor, transmittance, absorbance, and reflectance. One well knownelectrochromic material is tungsten oxide (WO₃). Tungsten oxide is acathodic electrochromic material in which a coloration transition,transparent to blue, occurs by electrochemical reduction.

Electrochromic materials may be incorporated into, for example, windowsfor home, commercial and other uses. The color, transmittance,absorbance, and/or reflectance of such windows may be changed byinducing a change in the electrochromic material, that is,electrochromic windows are windows that can be darkened or lightenedelectronically. A small voltage applied to an electrochromic device ofthe window will cause them to darken; reversing the voltage causes themto lighten. This capability allows control of the amount of light thatpasses through the windows, and presents an opportunity forelectrochromic windows to be used as energy-saving devices.

While electrochromism was discovered in the 1960's, electrochromicdevices, and particularly electrochromic windows, still unfortunatelysuffer various problems and have not begun to realize their fullcommercial potential despite many recent advancements in electrochromictechnology, apparatus and related methods of making and/or usingelectrochromic devices.

SUMMARY OF INVENTION

Methods of manufacturing electrochromic windows are described. Anelectrochromic (or “EC”) device is fabricated to substantially cover aglass sheet, for example float glass, and a cutting pattern is definedbased on one or more areas in the device from which one or moreelectrochromic panes are cut. In various embodiments, the cuttingpattern is defined, at least in part, only after the electrochromicdevice has been fabricated and characterized. In some cases, the cuttingpattern is defined after taking into account the overall quality of theelectrochromic device and/or the location of defects in the device. Forexample, the electrochromic device may be probed to determine thelocation of all defects or certain types or classes of defects. Thecutting pattern then excludes those defects from usable window panes,resulting in an overall high-quality product and a high-yield process.In another example, the complete device sheet is inspected to determinethe leakage current of the EC device or the resistivity of one or bothof the EC device's electrode layers. If the leakage current is higherthan a threshold or the resistivity of a TCO layer is higher than athreshold, the size of the electrochromic panes is limited to ensurethat the resulting windows perform adequately in spite of the device'shigh leakage or the TCO's high resistivity.

In certain embodiments, inspection of the glass sheet and/or individualpanes is performed at one or more points in the fabrication process.Various optical, electrical, chemical and/or mechanical metrology testsmay be used to probe the product, for example, after EC device formationin order to define a cutting pattern for the glass sheet and/or afterthe individual panes are cut to test the individual panes. Individuallayers of the EC device, the underlying substrate, etc. may beinspected. Inspection may include, for example, detection of defects inthe EC device and/or edges of the glass.

One or more edge portions of the glass sheet may be removed prior toand/or as part of the patterning process to remove potentialedge-related defects. Additionally, edges may be modified for strength,for example, by removing defects in the glass through mechanical and/oroptical treatment. Separately, defective areas throughout theelectrochromic device may be removed or mitigated by, for example,localized laser heating.

Laser scribes for isolating individual electrodes of EC devices on theindividual electrochromic panes may be added prior to or after cuttingthe panes. Similarly, bus bars for delivering power to the EC deviceelectrodes can be made before or after cutting the panes. A techniqueknown as edge deletion (described below) can also be performed prior toor after cutting the electrochromic panes from the glass sheet.

Insulated glass units (IGUs) are fabricated from the cut electrochromicpanes and optionally one or more of the panes of the IGU arestrengthened. In certain embodiments, strengthening is accomplished bylaminating glass or other reinforcing substrate to the cut panes. In aspecific embodiment, the lamination is performed after the IGU isassembled.

A method of manufacturing one or more electrochromic panes may becharacterized by the following operations: (a) fabricating anelectrochromic device on a glass sheet; (b) defining a cutting patternfor cutting the glass sheet in order to create the one or moreelectrochromic panes, the cutting pattern defined, at least in part, bycharacterizing the glass sheet and/or electrochromic device by one ormore physical features (characteristics) after fabrication of theelectrochromic device; and (c) cutting the glass sheet according to thecutting pattern to create the one or more electrochromic panes. In oneembodiment, characterizing the glass sheet and/or electrochromic deviceincludes identifying the one or more low-defectivity areas, scribing oneor more isolation trenches near one or more edges of the glass sheet,applying a temporary bus bar to the electrochromic device, andactivating the electrochromic device in order to evaluate theelectrochromic device for defectivity. Other methods of identifyingdefects, including areas of non-uniformity, in the EC device includeapplication of polarized light to the glass pane and the like. In oneembodiment, mapping data sets are created based on the one or morelow-defectivity areas and/or non-uniform areas on the electrochromicdevice and the data sets are compared in order to maximize efficient useof the glass sheet.

In some embodiments, electrochromic devices employ all non-penetratingbus bars on the individual electrochromic panes. In this way, moreviewable area is available in the electrochromic panes. The improvedelectrochromic panes may be integrated in IGUs and one or more of thepanes may contain a strengthening feature such as a laminated substrateof glass, plastic or other suitable material.

These and other features and advantages will be described in furtherdetail below, with reference to the associated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description can be more fully understood whenconsidered in conjunction with the drawings in which:

FIGS. 1A-B depict process flows describing aspects of fabricationmethods of the invention.

FIGS. 2A-B are schematics depicting aspects of fabrication methods ofthe invention.

FIG. 3A depicts liquid resin lamination of a reinforcing sheet to anIGU.

FIG. 3B depicts a cross section of the laminated IGU as described inrelation to FIG. 3A.

FIGS. 4A-B are cross section schematics depicting two side views of anelectrochromic device.

FIG. 4C is a schematic top view of the electrochromic device describedin relation to FIGS. 4A-B.

FIG. 5A is a cross section schematic showing the device described inrelation to FIGS. 4A-C integrated into an IGU.

FIG. 5B is a cross section schematic showing the IGU as in FIG. 5A,where the EC pane is strengthened by lamination.

DETAILED DESCRIPTION

For window applications, it is important that electrochromic panes beboth strong and relatively free of defects. Conventionally, glass panesare strengthened by tempering. Unfortunately, the tempering process canintroduce defects in an electrochromic device. Hence, most efforts toproduce electrochromic windows employ a fabrication sequence of firstcutting a glass pane to size, then tempering the glass, and finallyforming the electrochromic device on the tempered window pane. Theelectrochromic device is typically formed by depositing a sequence ofthin layers on one side of the pre-cut and tempered glass pane.Unfortunately, the described sequence of cutting and then forming the ECdevice frequently gives rise to some low quality electrochromic windowsbecause modern fabrication processes often produce one or more visibledefects on an electrochromic device. Of course, the manufacturer mayrefuse to tolerate low quality devices, but rejection of low qualitypanes corresponds to a reduction in yield.

As described herein, various fabrication methods can improve yield andquality. In these methods, initially an electrochromic device isfabricated to substantially cover a glass sheet. Only later is a cuttingpattern for multiple electrochromic panes defined on the glass sheet.The cutting pattern may take into account various considerationsincluding utilization of the sheet, defects in the EC device asfabricated, economic demand for particular sizes and shapes of EC panes,non-uniformity in the device and/or glass sheet, etc.

Frequently, problematic defects occur in only a very small or limitedregion or regions of the glass sheet. Once identified, these regions canbe excluded when defining electrochromic panes in the cutting pattern.In this manner, the cutting pattern may account for high (or low)defectivity regions of the glass sheet. While it is often desirable toprobe the EC device on the large glass sheet to identify and excluderegions of defects, it may sometimes be appropriate to exclude certainregions without probing the device. For example, it is sometimesobserved that defects are concentrated around the perimeter of the largeglass sheet. Therefore it is sometimes desirable to exclude theperimeter region from the pattern of electrochromic panes. In oneexample, between about 1 inches and about 10 inches around the perimeterof the glass sheet is removed after the electrochromic device isfabricated on the glass. In various embodiments, such perimeter regionsare excluded as a matter of course, with the exact amount of excludedperimeter region being based on a knowledge of the quality control (QC)of a well-defined production fabrication process.

Scribes and/or bus bars for the individual panes are provided at somepoint after the cutting pattern is defined. As mentioned, these featuresmay be provided to individual EC panes before and/or after the glasssheet is cut into one or more electrochromic panes according to thepattern. The cutting itself may employ a procedure that improves thestrength of the resulting cut panes. Further, as explained below, theedges may be “finished” to mitigate problems created by cutting.Additionally, in some embodiments, IGUs are fabricated from the cutelectrochromic panes and optionally one or more of the panes of the IGUare strengthened. More details of aspects of the invention are describedbelow and with respect to the Figures.

FIG. 1A depicts a process flow, 100, including a sequence of operationsfor manufacturing one or more electrochromic panes. First a glass sheetis received, see 110. For the purposes of the embodiments describedherein, a large glass sheet is intended to be cut into smaller panes ata later stage of the process. Typically, the panes are intended to beused as windows, so the physical dimensions as well as the optical andmechanical properties of the substrate should be appropriate for theintended window application. In a typical example, the large glass sheetemployed at operation 100 is a piece of glass of between about 3 metersand about 6 meters in length on at least one side. In some cases, theglass is rectangular, being about 3 to 6 meters high and about 1.5 to 3meters wide. In a specific embodiment, the glass sheet is about 2 meterswide and about 3 meters high. In one embodiment, the glass is six feetby ten feet. Whatever the dimensions of the glass sheet, the EC panefabrication equipment is designed to accommodate and process many suchsheets, fabricating EC devices on such sheets, one after another insuccession.

Suitable glass for the glass sheet includes float glass, Gorilla® Glass(a trade name for alkali-aluminosilicate sheet glass available from DowCorning, Corp. of Midland, Mich.) and the like. One of ordinary skill inthe art would recognize that EC devices can be formed on other thanglass substrates. Methods described herein are meant to include othersubstrates besides inorganic glass, for example, plexiglass would alsowork in some instances. For the purposes of simplicity, “glass sheet” isused from herein to encompass all types of window substrate, unlessotherwise specifically qualified.

In one embodiment, the glass sheet is float glass, optionally coatedwith a transparent conducting oxide (TCO) and a diffusion barrier layer.Examples of such glasses include conductive layer coated glasses soldunder the trademark TEC® Glass by Pilkington, of Toledo, Ohio andSUNGATE® 300 and SUNGATE® 500 by PPG Industries of Pittsburgh, Pa. Theglass sheet has a size that is at least equal to the largest EC glasspane contemplated for manufacture. TEC® Glass is a glass coated with afluorinated tin oxide conductive layer. Such glass typically also has adiffusion barrier layer between the TCO and the float glass to preventsodium from diffusing from the glass into the TCO. In one embodiment,the glass sheet does not have a preformed TCO or diffusion barrier onit, for example, in one embodiment the diffusion barrier, a first TCO,an electrochromic stack and a second TCO are all formed in a singleapparatus under a controlled ambient environment (infra). The glasssheet may be heat strengthened prior to fabrication of an electrochromic(EC) device thereon.

Next in the depicted process, an electrochromic (EC) device is preparedon the glass sheet, see 120. In the event that the glass sheet includesa pre-formed diffusion barrier and TCO, then the EC device uses the TCOas one of its conductors. In the event the glass sheet is float glasswithout any pre-formed coatings then typically 120 involves initiallydepositing a diffusion barrier layer, then a transparent conductor(typically a TCO) layer, and thereafter the remainder of the EC deviceis formed. This includes an EC stack having an electrochromic (EC)layer, a counter electrode (CE) layer and an ion conducting (IC) layer.After forming the EC stack, another transparent conductor layer(typically a TCO layer) is deposited as a second conductor (to deliverpower to the EC stack). At this point, the EC device is completed andoperation 120 is concluded. One or more capping layers may also beapplied. In one example, a hermetic layer is applied to keep moistureout of the device. In another example, a low-E (emissivity) coating isapplied.

As is understood by those of skill in the art, many different types ofelectrochromic devices exist, each having its own construction,electrode compositions, charge carrier, etc. Any of these devices may beemployed in the windows described herein. Certain embodiments aredescribed in relation to all solid state and inorganic electrochromicdevices. Such all solid-state and inorganic electrochromic devices, andmethods of fabricating them, are described in more detail in thefollowing U.S. patent applications: Ser. No. 12/645,111, titled,“Fabrication of Low-Defectivity Electrochromic Devices,” filed on Dec.22, 2009 and naming Mark Kozlowski et al. as inventors; Ser. No.12/645,159, titled, “Electrochromic Devices,” filed on Dec. 22, 2009 andnaming Zhongchun Wang et al. as inventors; Ser. Nos. 12/772,055 and12/772,075, each filed on Apr. 30, 2010, and Ser. Nos. 12/814,277 and12/814,279, each filed on Jun. 11, 2010—each of the latter fourapplications is entitled “Electrochromic Devices,” each names ZhongchunWang et al. as inventors. Each of the above patent applications isincorporated by reference herein for all purposes. In one embodiment,the electrochromic device is a low-defectivity all solid state andinorganic electrochromic device as described in the above applications.In one embodiment, the EC device is manufactured on the glass sheet inapparatus having a controlled ambient environment, that is, an apparatusin which the layers are deposited without leaving the apparatus andwithout, for example, breaking vacuum between deposition steps, therebyreducing contaminants and ultimately device performance. Thismanufacture may include deposition of a diffusion barrier on the glasssheet and the EC device including both electrodes (TCO layers).

As mentioned, inspections may be conducted internally at various pointsin the fabrication flow. For example, one or more of the TCO, EC, IC, CElayers may be inspected during processing. Optical, electrical,chemical, or mechanical inspections may be employed to characterize oneor more parameters of the layers. Such parameters include, for example,optical density, sheet resistance, thickness, defectivity, morphology,and the uniformity of any of these across the glass substrate surface.Separately one or more inspections may be performed after the entire ECdevice is fabricated on the glass sheet surface. As explained elsewhereherein, such inspection may characterize defectivity at regions on thesurface and/or non-uniformities in the EC device.

It would be understood by one of ordinary skill in the art that otherswitchable optical devices besides electrochromic devices may beemployed in the described process. Many such devices are formed aslayers on an underlying substrate. Examples of suitable optical devicesinclude various liquid crystal devices and electrophoretic devicesincluding rotating element and suspended particle devices. Any of thesecan be fabricated or otherwise provided on a large glass sheet and thenprocessed as described herein.

Referring again to FIG. 1A, once the EC device is prepared, a cuttingpattern is defined, see 130. As explained, defining a cutting patternafter depositing the electrochromic device affords considerableflexibility in determining which regions of the fabricated device areused and which are not used in the cut panes. It also, affordsflexibility in determining appropriate sizes of the panes based on theoverall quality of the fabricated electrochromic device. Of course,there are a range of considerations that drive the cutting pattern, andonly some of them pertain to the quality or condition of the asfabricated device. Overall, the characteristics used in defining apattern of EC panes on the glass sheet may include any one or more ofthe following: (1) local defectivity or other measure of local quality(for example, a local non-uniformity in sheet resistance), (2) demandfor particular grades of product (for example some end users specify aparticular grade or quality of EC pane), (3) demand for particular sizesand shapes of products, (4) remake demand (caused by breakages and/orlow yield fabrication of certain types of EC panes), (5) currentinventory of EC device types on the glass sheets and/or individual ECpanes, (6) utilization of the area of the overall glass sheet, and (7)global properties of the EC device (for example, EC device leakagecurrent and electrode (TCO) resistance). A global property might dictatethe appropriate size or grade of the final EC pane(s). For example, highEC device leakage current or high TCO resistance might indicate that theresulting EC panes must be relatively small (for example, not greaterthan about 20 inches). Stated another way, the glass sheets, each with afabricated EC device thereon, are binned based on global properties.

In some embodiments, one or more of the panes defined in the pattern aresized and shaped for residential window applications. In some cases, oneor more of the panes defined in the pattern are sized and shaped forcommercial window applications.

Based on the considerations above, defining a cutting pattern forcutting the glass sheet in order to create the one or moreelectrochromic panes can include characterizing one or more physicalfeatures of the glass sheet and/or electrochromic device afterfabrication of the electrochromic device. In one embodiment,characterizing the one or more physical features include at least oneof: 1) identifying one or more low-defectivity areas on theelectrochromic device, 2) identifying one or more areas ofnon-uniformity in the electrochromic device, 3) identifying one or moreareas where materials used to make the electrochromic device weredeposited on the back side of the glass sheet; 4) identifying one ormore performance characteristics of the electrochromic device; and 5)identifying one or more defects in the glass sheet. Identifying one ormore low-defectivity areas in the electrochromic device is described inmore detail below. Non-uniform areas in the EC device are, for example,areas where, for example, the coloration is not uniform due to variationin thickness of layers of the EC device, variation in properties of thedevice, for example, due to uneven heating during formation of the ECstack, and the like. Non-uniform areas thus may be independent of thenumber of, for example, short related optical defects. It may bedesirable to remove these areas from the cutting pattern or include themin the cutting pattern but identify them as, for example, being areasfrom which a different quality of EC pane will be cut. Also, dependingon the process conditions, materials used to make the electrochromicdevice can be deposited on the back side of the glass sheet due tooverspray. This is undesirable and therefore the presence of backsidedeposition is a useful characteristic of the glass sheet after EC deviceformation. Areas with backside materials may be cleaned to remove theunwanted material and/or these areas are excluded from the cuttingpattern. Performance characteristics of the electrochromic device arealso an important parameter for characterizing the EC device. Asdescribed above, for example, an EC device may be used in different waysdepending on whether it falls into a certain specification category.Identifying one or more defects in the glass sheet is also important,for example, irrespective of the EC device's performance, there may be adefect in the glass sheet, like a bubble or fissure trapped in theglass, that would be excluded from the cutting pattern due to itsundesirable optical properties.

In a specific embodiment, the cutting pattern is defined (operation 130of FIG. 1A) by first detecting and mapping the defectivity of the deviceacross the glass sheet and then excluding or relegating areas of highdefectivity from one or more electrochromic panes in the cuttingpattern. FIG. 1B provides an example process flow for this embodiment.First, as depicted in block 131, the glass sheet's device is scribed inorder to define a usable area, which is typically substantially theentire area of the device as prepared on the glass sheet. The scribingmay serve two purposes. First it electrically isolates the twoelectrodes to provide a functioning device, and second it removesclearly defective portions of the EC stack. In some cases, deposited ECfilms in edge regions of the glass sheet exhibit roll off and/or otherimperfections, and thus present the very real issue of short circuits.To address this problem, the edge regions of the device are isolated orremoved. Techniques for accomplishing this include scribing (presentedin FIG. 1B), edge deleting, or simply removing the glass sheet andassociated device over some fraction of the perimeter.

After the scribe, temporary bus bars are applied, see 132. Then thedevice is activated by application of electrical energy to color orotherwise change the optical properties of the device so that the devicecan be characterized and any defects can be detected, see 133. Thendevice is characterized including identifying any defects and optionallyclassifying the defects as to type and/or severity, see 134. In someembodiments, non-uniformities in the EC device are characterized at thisstage as well, and taken into account when defining the cutting pattern.In some embodiments this characterization includes the glass pane aswell as the EC device on the glass pane. In some examples, theidentification and/or classification is performed by the naked eye. Inother examples, this operation is performed by an automated scanningdevice. In one embodiment, larger short-type visual defects aremitigated by application of electrical or optical energy. In a specificembodiment, such defects are circumscribed by laser ablation to createsmaller pin-hole type defects. These mitigated defects may be includedin the defect count when identifying regions of low defectivity. Inanother embodiment, this ablation or other mitigation is performed afterthe panes are cut from the glass sheet.

It should be understood that activating the EC device and scrutinizingthe device is only one way to detect and identify defects. Other methodsinclude using diffraction, reflection, or refraction of various forms ofelectromagnetic radiation that interact with the EC device, for example,polarized light and/or lock-in infrared (IR) thermography. Lock-in IRthermography is a non-destructive and non-contacting technique for thespatially resolved detection of small leakage currents in electronicmaterials that involves applying a temperature source to the material(in this case the EC device) and detecting leakage current inducedtemperature variations with, for example, an infrared camera. Thus,embodiments include not only activating the EC device to identifydefects, but also may include, or use in the alternative, other methodsof identifying defectivity.

As indicated, the cutting pattern defined on the glass sheet may excludeone or more high-defectivity areas of the electrochromic device providedon the glass sheet. Thus, the fabrication sequences contemplated hereinfrequently involve identifying regions of low or high defectivity priordefining a cutting pattern. In certain embodiments, “low-defectivity”areas are regions of the electrochromic device with fewer than athreshold number or density of defects. Defects may be identified andcharacterized in various ways. In certain embodiments, defects areidentified and/or classified as described in U.S. patent applicationSer. Nos. 12/645,111 and 12/645,159, both previously incorporated byreference.

In certain specific embodiments, only visual defects are considered whendefining a cutting pattern. Visual defects include short-type defectsthat produce a halo when the device is darkened. A halo is a region inthe device where an electrical short across the electrochromic stackcauses an area around the short to drain current into the short andtherefore the area surrounding the short is not darkened. These shortdefects are conventionally treated after fabrication of theelectrochromic device, for example laser circumscribed to isolate themand remove the halo effect, which leaves smaller short-related pinholedefects. In a typical example, defects visible to the naked eye are onthe order of 100 μm in diameter. In one embodiment, for defects of thesize regime greater than 100 μm, the total number of visible defects,pinholes and short-related pinholes created from isolating visibleshort-related defects, in a low-defectivity area is less than about 0.1defects per square centimeter, in another embodiment less than about0.08 defects per square centimeter, in another embodiment less thanabout 0.045 defects per square centimeter (less than about 450 defectsper square meter of electrochromic pane). Smaller defects, for exampledefects not visible to the naked eye (on the order of 40 μm or less),may be tolerable in higher densities in some embodiments.

The defects that are detected and optionally classified in the glasssheet are mapped, see operation 135 of FIG. 1B. This can be done, forexample, by marking the glass to show where the defects are located oncethe device is inactive, and/or by storing the defect pattern in a memoryas a map. This mapping information is analyzed to identify one or morelow-defectivity regions from which to cut the one or more EC panes, see136. One embodiment of the depicted method defines the cutting patternby (a) creating a first mapping data set based on the one or morelow-defectivity areas on the electrochromic device; (b) creating asecond mapping data set based on another one or more low-defectivityareas on a second electrochromic device on a second glass sheet; (c)comparing the first and second mapping data sets; and (d) defining thecutting pattern using the comparison of the first and second mappingdata sets to maximize efficient use of the glass sheet. For example, themapping may be used to match two compatible EC sheets for use in asingle IGU so that defects in the respective panes do not align. In oneimplementation, the first and second mapping data sets are stored in amemory and (c) and (d) are performed using an appropriate algorithm orother logic. Thus, these mapping data sets and comparisons thereofdefine the most efficient use of the glass sheet's device. For example,mapping data for two glass sheets may indicate that the most efficientuse of the glass would be to cut the two sheets to accommodate differentcustomers' specifications due to defectivity patterns that, if notpresent, would otherwise dictate cutting the sheets according to asingle customer's specifications. Additionally, the logic may definepanes of varying sizes from each glass sheet in order to supplyelectrochromic panes for a variety of window types and end users, forexample, by pane size, defectivity level and the like. Once the one ormore low-defectivity regions are used to define the cutting pattern andprocess flow 130 ends.

FIG. 2A depicts a glass sheet, 200, for example about 3 meters by about2 meters, or about 120 inches by 72 inches, with an EC device (not shownseparately) thereon. In this example, in accord with process flow 100, acutting pattern (as indicated by the dotted lines) is defined forcutting one or more electrochromic panes from glass sheet 200. Dependingupon, for example, the defectivity, demand or other parameters describedabove, the cutting pattern can be regular, such as pattern 202, orirregular, such as pattern 204. Pattern 204 shows, for example, areas206 a and 206 b, which collectively make a strip of glass that is to bediscarded due to, for example, roll off and/or higher defect levels thanthe rest of the glass sheet. These perimeter areas may also be removedbecause of back side contamination of EC device materials due tooverspray. From a single glass sheet, the one or more EC panes can be ofthe same size, or varying size depending on the need.

In some embodiments, prior to cutting the glass sheet, some or all edgesof the sheet may be removed. In some embodiments about 1 to 10 inches ofglass are removed around some or all of the glass sheet's perimeter.This edge trimming can be done for a variety of reasons. For example,the quality of the EC device may be inferior around the perimeter of theglass sheet. This low quality around the perimeter may be due to rolloffof the EC device stack, imperfections in the edge of the glass sheet(which can interfere with the EC device fabrication), propagation ofsuch edge defects (e.g. fissures), and cathode dimensions as they relateto the glass sheet dimensions during deposition. Also, deposition ofmaterials on the back side of the glass sheet due to overspray maynecessitate trimming the edges of the glass. Non-uniformities in the ECdevice may occur due to contact of the support pallet during processingof the EC device or non-uniform heating near the edges of the glass.Some of these defects can be appreciated without powering the EC deviceand therefore edge trimming may be performed prior to testing thedevice. Thus edge trimming may be performed as a matter of course or asa result of, for example, performing test runs of the EC formation andfinding that the process parameters require that edge trimming beperformed post device fabrication to remove non-uniformities and/or backside overspray.

Referring again to FIG. 1A, after the cutting pattern is defined for theone or more EC panes, scribes are performed according to the needs ofeach individual EC pane to be cut from the glass sheet, see 140. A moredetailed description of scribes used to fabricate individual EC panes isdescribed below in relation to FIGS. 3A-C. In this process flow, thescribes are made prior to the individual EC panes being cut from theglass sheet. This saves time and resources that would otherwise beneeded in order to scribe the individual panes, since a wide variety ofpane sizes are contemplated as arising from the single glass sheet. Inother embodiments, the scribes are made after the glass sheet is cutinto individual EC panes (infra).

In the depicted example, after the EC devices on the glass sheet havebeen scribed, they are cut from the glass sheet according to the cuttingpattern, see 150. The cutting can be accomplished by any suitableprocess. In some cases, the cutting is accompanied by an edge finishingoperation. Mechanical cutting typically involves scoring the glass witha hard tool, such as a diamond tip on a wheel, followed by snapping theglass along the score line. Thus, mechanical cutting includes “scoring”and breaking. Sometimes the term “scoring” is referred to as “scribing”in the glass window fabrication industry. However, to avoid confusionwith other operations described herein, use of “scribe” will be reservedfor these other operations.

Cutting can produce microcracks and internal stresses proximate the cut.These can result in chipping or breaking of the glass, particularly nearthe edges. To mitigate the problems produced by cutting, cut glass maybe subject to edge finishing, for example, by mechanical and/or lasermethods. Mechanical edge finishing typically involves grinding with, forexample, a grinding wheel containing clay, stone, diamond, etc.Typically, water flows over edge during mechanical edge finishing. Theresulting edge surface is relatively rounded and crack free. Laser edgefinishing typically produces a flat, substantially defect free surface.For example, an initial cut through the glass, perpendicular to thesurface of the glass, may make a substantially defect free cut. Howeverthe right angle edges at the perimeter of the glass are susceptible tobreakage due to handling. In some embodiments, a laser is usedsubsequently to cut off these 90 degree edges to produce a slightly morerounded or polygonal edge.

Examples of cutting and optional edge finishing processes include thefollowing: (1) mechanical cutting, (2) mechanical cutting and mechanicaledge finishing, (3) laser cutting, (4) laser cutting and mechanical edgefinishing, and (5) laser cutting and laser edge finishing.

In one embodiment, the panes are cut from the glass sheet in a mannerthat actually strengthens and/or improves the edge quality of theresulting panes. In a specific example, this is accomplished using laserinduced scoring by tension. In this method, a gas laser, for example aCO₂ laser with a wavelength of 10.6 μm, is used to heat the surface ofthe glass along a cut line to produce a compressive stress in the glassalong the cut line. A cooling device, for example a gas and/or waterjet, is used to quickly cool the heated line. This causes a score toform in the glass along the cutting line. The glass is then snapped by,for example, a conventional mechanical breaking device along the score.Using this method, the cut lines are extremely clean, that is, there areminimal if any defects in the glass that can propagate and cause furtherbreakage due to stresses applied to the pane. In one embodiment, theedges are subsequently mechanically and/or laser finished to remove the90 degree edges to create a more rounded and/or polygonal edge.

Referring again to FIG. 1A, optionally, edge deletion is carried out onthe individual EC panes, see 160. Edge deletion is part of amanufacturing process for integrating the electrochromic device into,for example an IGU, where edge portions of the EC device, for exampleroll off (where layers of the device can make contact due tonon-uniformity near the edge of for example a mask) and/or where a cutis made, are removed prior to integration of the device into the IGU orwindow. Where unmasked glass is used, removal of the coating that wouldotherwise extend to underneath the IGU frame (which is undesirable forlong term reliability) is removed prior to integration into the IGU.Edge deletion is also used when a pane is cut from the glass sheet, asthe panes will have EC material running to the edges of the pane. In oneembodiment, isolation trenches are cut and the isolated portions of theEC device on the perimeter of the panes is removed by edge deletion.Edge deletion can be performed at any stage post formation of the ECdevice in the process flows described. The process of performing edgedeletion is, in some embodiments, a mechanical process such as agrinding or sandblasting process. An abrasive wheel may be employed infor grinding. In one embodiment, edge deletion is done by laser, forexample, where a laser is used to ablate EC material from the perimeterof the pane. The process may remove all EC layers including theunderlying TCO layer or it may remove all EC layers except this bottomTCO layer. The later case is appropriate when the edge delete is used toprovide an exposed contact for a bus bar, which must be connected to thebottom TCO layer. In some embodiments, a laser scribe is used to isolatethat portion of the bottom TCO that extends to the edge of the glassfrom that which is connected to the bus bar in order to avoid having aconductive path to the device from the edge of the glass.

When edge deletion is to be used, it can be done before or after the ECpanes are cut from the glass sheet. In certain embodiments, edgedeletion may be carried out in some edge areas prior to cutting the ECpanes, and again after they are cut. In certain embodiments, all edgedeletion is performed prior to cutting the panes. In embodimentsemploying “edge deletion” prior to cutting the panes, portions of the ECdevice on the glass sheet can be removed in anticipation of where thecuts (and thus edges) of the newly formed EC panes will be. In otherwords, there is no actual edge yet, only a defined area where a cut willbe made to produce an edge. Thus “edge deletion” is meant to includeremoving EC device material in areas where an edge is anticipated toexist.

Referring again to FIG. 1A, after the optional edge deletion, bus barsare applied to the one or more EC panes, see 170. As with edge deletion,the addition of bus bars can be performed after the EC panes are cutfrom the glass sheet or before, but after scribing. By performing thescribe, edge deletion and bus bar application prior to cutting the panesfrom the glass sheet, the associated special handling steps for avariety of EC pane sizes are avoided. That is, performing variousmanipulations and/or component integrations before the individual panesare cut from the glass sheet allows use of apparatus for handling theglass sheets of uniform size for maximum efficiency. However, in oneembodiment, the glass sheet is cut according to 150, then edge deletionis performed according to 160, and thereafter the EC devices are scribedaccording to 140. In this embodiment, edge deletion is performed at theedges of the individual EC panes, and then the scribes are applied. Inanother embodiment, the glass sheet is cut according to 150, then the ECdevices are scribed according to 140, and then edge deletion isperformed according to 160. One advantage of scribing and deleting postcutting is uniformity in the edge deletion process, since only materialfrom the perimeter where actual cut edges (rather than from areas wherean edge is anticipated to exist post cutting) is removed. This methodmay include higher quality control since the edge of the glass can beused as a guide for the edge deletion.

After the panes with fully assembled EC devices are completed, IGUs aremanufactured using the one or more EC panes, see 180. Typically, an IGUis formed by placing sealing separator, for example, a gasket or seal(for example made of PVB (polyvinyl butyral), PIB or other suitableelastomer) around the perimeter of the glass sheet. In some embodiments,the sealing separator includes a metal, or other rigid material, spacerand sealant between the spacer and each glass pane. After the panes aresealed to the spacer, a secondary seal is provided around the outerperimeter of the spacer, for example a polymeric material that resistswater and that adds structural support to the assembly. Typically, butnot necessarily, a desiccant is included in the IGU frame or spacerduring assembly to absorb any moisture. In one embodiment, the sealingseparator surrounds the bus bars and electrical leads to the bus barsextend through the seal. Typically, but not necessarily, the IGU isfilled with inert gas such as argon. The completed IGU can be installedin, for example, a frame or curtain wall and connected to a source ofelectricity and a controller to operate the electrochromic window.

Referring to FIG. 2B, glass sheet 200 is cut according to a cuttingpattern derived, for example, as described herein. In this example four(EC) panes, 208, are produced. Further, in this example, two of panes208 are paired and combined with a sealing separator, 210, to form anIGU, 212. In this example, IGU 212 has two EC panes. Typically, but notnecessarily, the panes are arranged so that EC devices face inside theIGU so as to be protected from the ambient. Electrochromic windowshaving two or more electrochromic panes are described in U.S. patentapplication Ser. No. 12/851,514, filed on Aug. 5, 2010, and entitled“Multipane Electrochromic Windows,” which is incorporated by referenceherein for all purposes. Methods described therein are particularlyuseful for making one or more electrochromic panes for use in multipaneelectrochromic windows. One advantage to such multipane electrochromicwindows is that the likelihood of two defects aligning perfectly, andthus being observable to the end user, is quite small. This advantage isaccentuated when low-defectivity panes are used. In embodiments where,for example, two electrochromic panes are used in a single window, theaforementioned (defect) mapping data sets can be used to further ensurethat defects on individual panes, when registered in an IGU, do notalign. This is yet another criterion that may be considered inpatterning the glass sheet.

In certain embodiments, the glass sheet is up to 5 mm or even up to 6 mmthick (up to ¼ inch). In some embodiments, one or more panes arestrengthened. Referring again to FIG. 1A, optionally, one or both panesof the IGU are strengthened, see 190. For example, in one embodiment,strengthening includes laminating one or more of the panes of the IGUwith, for example, a thicker pane of float glass, a pane of temperedglass, a polymeric pane such as plexiglass, Gorilla® Glass, and thelike. In another embodiment, strengthening includes applying a polymericcoating to one or more panes of the IGU. Examples of such polymericcoatings include ormosil polymeric coatings (epoxy resin, an aminehardener and a silane), sol-gel coatings, acrylic glazes, and othersafety glazes, for example commercially available glazes which meet oneor more impact test standards. Referring again to FIG. 1A, after one ormore panes of the IGU are strengthened, process flow 100 ends.

In some embodiments, an edge bumper is employed to protect the edges ofthe glass after incorporation in the IGU. The protection allows the IGUto be safely transported from manufacturer to installation, for example.A protective edge bumper may be applied to IGUs with or withoutstrengthened panes. In one embodiment, the protective bumper is aU-channel cap which fits over the glass edges around the perimeter ofthe IGU. It may be made from an elastomeric or plastic material. In oneexample, it is a vinyl cap.

Laminating an EC pane with a reinforcing substrate (or pane) afterincorporation into an IGU has many benefits. For example, laminationafter the EC pane is assembled in an IGU protects the EC device duringthe lamination process and provides ease of handing. This isparticularly true if the EC device is on an inner facing surface of theIGU, that is, in the interior insulating region of the IGU, becauselamination processes involve contacting the outer surfaces of the glasspanes making up the lamination structure under relatively harshconditions. Under such conditions, the EC device would be damaged if itwas located on the outer surface of a lamination structure. The IGU thusprotects the device during lamination. If the EC device is located on anouter facing surface of glass on the IGU, lamination of the EC panewould require lamination directly onto the EC device with thereinforcing pane and/or the adhesive used to attach it (the laminationpane). While lamination can be conducted without damaging the EC device,this approach has some downsides. Most notably, the IGU would be a lesseffective thermal insulator because radiation is blocked only at theinterior of the IGU. Further, the exposed edges of the EC device,located around the perimeter of the IGU, may provide an ingress pointfor moisture after installation.

Many different lamination processes can be employed in the disclosedembodiments. Examples include roll pressing and autoclaving, vacuumbagging, and liquid resin lamination, each of which is well known in thewindow fabrication industry. In one embodiment, liquid resin laminationis used to strengthen an EC pane after it is incorporated into an IGU.

FIG. 3A schematically depicts aspects of a process flow for liquid resinlamination of an IGU, 300. In FIG. 3A, IGU 300 is drawn in less detailthan for example IGU 212 described in relation to FIG. 2B. In thisexample, IGU 300 has an EC pane and a non-EC pane. Typically, doublesided tape, 305, is applied to a perimeter region of the EC pane. A gap,315, is left in the perimeter tape, for example, in a corner of thepane. A reinforcing pane, 310, is applied to the double-sided tape, sothat a triple pane (see also FIG. 3B, in this example, the reinforcingpane is laminated to the EC pane of the IGU, and there is also thenon-EC pane of the IGU which is not part of the laminate) structure,320, is formed. A liquid resin, 325, is introduced, for example from thebottom as depicted, in the volume formed between the EC pane andreinforcing pane 310. This can be accomplished, for example, by leavinga small portion of the backing of the tape on when pane 310 is appliedto the tape and registered with the EC pane. A dispensing nozzle, in theshape of a thin blade, is inserted in between pane 310 and the portionof the tape with the backing remaining. After the resin is introducedinto the volume and the blade removed, the remaining tape backing isremoved so that the only means of exit for the resin is gap 315. Asindicated by the curved and dotted heavy arrows, unit 320 is thenrotated so that the liquid resin 325 flows toward gap 315 (as indicatedin the lower left diagram by the heavy dotted arrow downward). Theappropriate amount of resin is introduced into the volume so that whenthe resin covers the entire area between the panes and within the tape,the panes are substantially parallel to each other. Once the volume isfilled with resin, the resin is cured, for example, via heating, acatalyst and/or exposure to UV irradiation to form a strong bond betweenthe panes. In the final assembly, as depicted in the lower right of FIG.3A, the cured resin has the desired optical, mechanical and otherproperties of the lamination. Using liquid resin lamination impartsminimal if any stress on the EC pane during lamination.

FIG. 3B is a cross section showing more detail of the final assembly320. The IGU portion, 300, includes a first pane, 301, and an EC pane,302, which includes an EC device, 303, thereon. Panes 301 and 302 areseparated by a sealing separator, 304, which spans the perimeter of thepanes and has seals between it and each pane. An interior space, 330, isdefined by the panes and the sealing separator. Tape 305 lies between(and proximate to the perimeter) of the face of the EC pane outside ofthe IGU's interior space and pane 310. Inside the volume created betweenthe EC pane and pane 310 is the cured resin, 325.

Because resin based lamination relies on a sheet or film of resinsandwiched between the two glass panes to be laminated, choice of resintype can impart an optical characteristic to the window unit. In certainembodiments, the resin may contain additives that impart a desiredoptical property to the resulting laminate. Examples of such opticalproperties include color, opacity, scattering and reflectivity. In aspecific example, the resin imparts a blue color. This can beparticularly beneficial when used with some EC devices that have anaturally yellowish tint. The optical property can be imparted by addingdyes, pigments, scattering particles, metallic dust, etc. to the liquidresin prior to introduction into volume for lamination. In certainembodiments, the blue color is achieved as a result of a chemicalreaction that takes place after the resin is introduced into the volumebetween the panes. For example, the reaction may be catalyzed by thesame energy or reagent that catalyzes the curing of the resin. Inanother embodiment, the resin changes to a blue color after curing, forexample, by exposure to normal ambient lighting and/or specificirradiation and/or heating post cure.

Particular examples of electrochromic panes are described with referenceto FIGS. 4A-C. FIG. 4A is a cross-sectional representation of anelectrochromic pane, 400, which is fabricated starting with a glasssheet, 405, for example as outlined in process flow 100. FIG. 4B showsthe cross sectional view from another side of EC pane 400, and FIG. 4Cshows a top view of EC pane 400 (FIG. 4A is the view from the right orleft side as depicted in FIG. 4C; and FIG. 4B is the view from thebottom side looking up as depicted in FIG. 4C). FIG. 4A shows theindividual electrochromic pane after it has been cut from the glasssheet, edge deleted, laser scribed and bus bars have been attached. Theglass pane, 405, has a diffusion barrier, 410, and a first transparentconducting oxide (TCO) 415 on the diffusion barrier. The TCO layer 415is the first of two conductive layers used to form the electrodes of theelectrochromic device fabricated on the glass sheet. In this example,the glass sheet includes underlying glass and the diffusion barrierlayer. Thus in this example, the diffusion barrier is formed, then thefirst TCO, then the EC stack, and then the second TCO. In oneembodiment, the electrochromic device (EC stack and second TCO) isfabricated in an integrated deposition system where the glass sheet doesnot leave the integrated deposition system at any time duringfabrication of the stack. In one embodiment, the first TCO layer is alsoformed using the integrated deposition system where the glass sheet doesnot leave the integrated deposition system during deposition of the ECstack and the (second) TCO layer. In one embodiment, all of the layers(diffusion barrier, first TCO, EC stack and second TCO) are deposited inthe integrated deposition system where the glass sheet does not leavethe integrated deposition system during deposition.

After formation of the EC device, edge deletion and laser scribes areperformed. FIG. 4A depicts areas 440 where the device has been removed,in this example, from a perimeter region surrounding the laser scribetrenches, 430, 431, 432 and 433, which pass through the second TCO andthe EC stack, but not the first TCO, are made to isolate portions of theEC device, 435, 436, 437 and 438, that were potentially damaged duringedge deletion from the operable EC device. In one embodiment, laserscribes 430, 432, and 433 pass through the first TCO to aide inisolation of the device (laser scribe 431 does not pass through thefirst TCO, otherwise it would cut off bus bar 2's electricalcommunication with the first TCO and thus the EC stack). The laser orlasers used for the laser scribes are typically, but not necessarily,pulse-type lasers, for example diode-pumped solid state lasers. Forexample, the laser scribes can be performed using a suitable laser fromIPG Photonics (of Oxford Mass.), or from Ekspla (of Vilnius Lithuania).Scribing can also be performed mechanically, for example, by a diamondtipped scribe. One of ordinary skill in the art would appreciate thatthe laser scribes can be performed at different depths and/or performedin a single process whereby the laser cutting depth is varied, or not,during a continuous path around the perimeter of the EC device. In oneembodiment, the edge deletion is performed to the depth below the firstTCO. In another embodiment, a second laser scribe is performed toisolate a portion of the first TCO, for example as depicted in FIGS.4A-C, near the edge of the glass pane from that toward the interior. Inone example this scribe is at least along the edge where bus bar 2 isapplied to the first TCO, between bus bar 2 and the edge.

After laser scribing is complete, bus bars are attached. Non-penetratingbus bar (1) is applied to the second TCO. Non-penetrating bus bar (2) isapplied to an area where the device was not deposited (for example froma mask protecting the first TCO from device deposition), in contact withthe first TCO or in this example, where edge deletion was used to removematerial down to the first TCO. In this example, both bus bar 1 and busbar 2 are non-penetrating bus bars. A penetrating bus bar is one that istypically pressed into and through the EC stack to make contact with theTCO at the bottom of the stack. A non-penetrating bus bar is one thatdoes not penetrate into the EC stack layers, but rather makes electricaland physical contact on the surface of a conductive layer, for example,a TCO.

The TCO layer's can be electrically connected using a non-traditionalbus bar, for example, screen and lithography patterning methods. In oneembodiment, electrical communication is established with the device'stransparent conducting layers via silk screening (or using anotherpatterning method) a conductive ink followed by heat curing or sinteringthe ink. Advantages to using the above described device configurationinclude simpler manufacturing, for example, less laser scribing thanconventional techniques which use penetrating bus bars, and the factthat the EC device colors to, and under, bus bar 1 (unlike conventionalmethods which cut an isolation trench through the device when bus bar 1is a penetrating type bus bar), which provides a larger coloration area.Penetrating bus bar's can be used, for example in place ofnon-penetrating bus bar 1, but this will sacrifice colorable area andwould necessitate a scribe through the first TCO, prior to fabricationof the EC stack on the glass. One embodiment contemplates performingthis first scribe for the one or more EC devices on the glass sheetprior to fabrication of the EC device thereon. In such embodiments, theremainder of the method flow, for example as described in relation toFIGS. 1A and 1B, remains analogous.

As described above, after the bus bars are connected, the device isintegrated into an IGU, which includes, for example, wiring the bus barsand the like. In some embodiments, one or both of the bus bars areinside the finished IGU, however in one embodiment one bus bar isoutside the seal of the IGU and one bus bar is inside the IGU. FIG. 5Adepicts a cross section of the EC pane as described in relation to FIGS.4A-C integrated into an IGU, 500. A spacer, 505, is used to separate ECpane 400 from another pane, 510. The second pane 510 in this example isa non-EC pane, however the invention is not so limited. Pane 510 canhave an EC device thereon and/or one or more coatings such as low-Ecoatings and the like. Between spacer 505 and, in this example, thefirst TCO of EC device 400, is a primary seal, 515. This seal is alsobetween separator 505 and the second glass pane. Around the perimeter ofseparator 505 is a secondary seal, 520 (bus bar wiring traverses theseal for connection to controller). These seals aid in keeping moistureout of the interior space, 515, of the IGU.

FIG. 5B depicts IGU 500 after lamination with a reinforcing pane, 530.In this example a liquid resin lamination was used, and thus, curedresin, 535, lies between the reinforcing pane and the glass of the ECpane. Although not depicted, one of ordinary skill in the art wouldappreciate that if glass 2 also had an EC device thereon, it could alsobe laminated. One embodiment is an IGU including two EC panes separatedby an interior space, in one example both EC devices are in the interiorspace of the IGU, where both EC panes are reinforced. In one embodiment,the EC panes are reinforced with liquid resin lamination as describedherein. In other embodiments, one or both of the EC panes are reinforcedor strengthened by applying a coating as described herein.

Although the foregoing invention has been described in some detail tofacilitate understanding, the described embodiments are to be consideredillustrative and not limiting. It will be apparent to one of ordinaryskill in the art that certain changes and modifications can be practicedwithin the scope of the appended claims.

1-26. (canceled)
 27. An insulated glass unit, comprising: a first panehaving a laminate, the laminate comprising a substrate having anelectrochromic device disposed thereon and a reinforcing substratelaminated together with a lamination layer, wherein the lamination layeris configured to modify at least one optical property of the insulatedglass unit; a second pane; a spacer between the first pane and thesecond pane; and a primary seal for bonding the first pane to the spacerand the second pane to the spacer.
 28. The insulated glass unit of claim27, wherein the at least one optical property comprises one of color,opacity, scattering and reflectivity.
 29. The insulated glass unit ofclaim 27, wherein the lamination layer is configured to modify color ofthe insulated glass unit to impart a blue color.
 30. The insulated glassunit of claim 27, wherein the lamination layer comprises a compensatingoptical property.
 31. The insulated glass unit of claim 27, wherein thelamination layer comprises a resin.
 32. The insulated glass unit ofclaim 31, wherein the resin comprises one or more of a dye, a pigment, ascattering particle, and metallic dust.
 33. The insulated glass unit ofclaim 31, wherein the resin is a liquid resin before curing.
 34. Theinsulated glass unit of claim 33, wherein the liquid resin is cured byheating, a catalyst, and/or exposure to ultraviolet radiation.
 35. Theinsulated glass unit of claim 27, wherein the substrate having anelectrochromic device disposed thereon and the reinforcing substrate arelaminated together by at least one of roll pressing and autoclaving,vacuum bagging, and liquid resin lamination.
 36. The insulated glassunit of claim 27, wherein the reinforcing substrate is laminateddirectly to the electrochromic device.
 37. The insulated glass unit ofclaim 27, wherein the substrate having an electrochromic device disposedthereon is annealed glass.
 38. The insulated glass unit of claim 37,wherein the reinforcing substrate is tempered glass.
 39. The insulatedglass unit of claim 27, wherein the reinforcing substrate is thickerthan the substrate having the electrochromic device thereon.
 40. Theinsulated glass unit of claim 27, wherein the reinforcing substratecomprises one of float glass, tempered glass, and a polymeric material.41. The insulated glass unit of claim 40, wherein the polymeric materialis plexiglass.
 42. The insulated glass unit of claim 27, wherein theelectrochromic device is disposed on an inner facing surface of aninterior volume between the first pane and the second pane.
 43. Theinsulated glass unit of claim 27, wherein the electrochromic device isall solid state and inorganic.
 44. The insulated glass unit of claim 27,further comprising bus bars disposed on electrodes of the electrochromicdevice.
 45. The insulated glass unit of claim 27, further comprisinganother electrochromic device disposed on the reinforcing substrate ofthe laminate.